qr code

This bar code tattoo was sent into us by [Lifespan]. Before going under the needle, [Lifespan] didn’t care much for tattoos. After seeing this video he realized that a tattoo could have dynamic content through domain redirection.

[Lifespan] spent a lot of time going over the different styles of 2D bar codes. QR codes were deemed ugly because of the three large squares in the corners. An EZ Code, like the one in his YouTube inspiration, are a proprietary format that must be read with a ScanLife app. He eventually settled on a Data Matrix bar code because of its open format and ubiquity in business and industry. To make the tattoo dynamic, [Lifespan] made the tattoo point to 5id5.com. With a little bit of smart phone wizardry, that domain can be redirected to any URL in a moments notice.

Like all well-planned tattoos, he found himself a very good artist to do the piece. [Connor Moore] managed to ink some skin at 15 dpi, which was a little risky, but the results came out great. While it’s not scarification via a laser cutter, barring fading this tattoo is technologically future proof.

After writing this post on somone hacking QR codes, Hack A Day commenters came out in full force posting some really cool links about modifying QR codes to include a logo. I’ll fully admit I geeked out a little, but in the process I figured out some of the theory behind embedding logos in QR codes.

After getting my hands on the ISO 18004 specification for QR codes, I decided to try embedding the Hack A Day skull & wrenches inside a QR code. The tools I used were Photoshop, this QR code generator, and Microsoft Paint (I’ve never seen a program to edit individual pixels that has a better UI, so don’t laugh).

QR codes are everywhere these days, from being printed onto receipts to chiseled into granite tombstones. [Will] came up with a way to modify existing QR codes, and his hack has the potential to cause quite a bit of harmless mischief.

[Will]’s hack involves a little photo editing, transparency film, and some white-out/Liquid Paper/Tippex. After the ‘target’ and ‘destination’ QR codes have been imported into Gimp, the differences are found and the result printed out on a transparency sheet. After that, hang the transparency over the original and the QR code now goes to the URL of your choice.

[Scott Harden] came across a few posts about QR code matrix barcodes coming through on the 40m baud radio band. A few operators had captured the signals and assembled them into the code block seen above but they weren’t able to get a clear enough shot for a smartphone to decode the image. [Scott] took on the challenge and decoded the mysterious message himself. He tried some graphic editing to separate and enhance the color channels in order to up the contrasts of the image. This helped, but still couldn’t be read automatically. In a move similar to those seen in Hackaday’s own barcode challenges he dropped the image into Inkscape so that he could manually clean it up. Once it was overlaid on a grid the job was pretty simple. the left side did require some more image manipulation and precision”squinting” to eliminate interference from the vertical banding, but he managed to get the message. We won’t spoil it here in case you want to take on the challenge yourself. Good luck!